1. Field of the Invention
This invention relates to footwear, in general, and to footwear having electronic circuitry associated therewith for measuring parameters of usage of the footwear, in particular.
2. Prior Art
It has been previously known to provide footwear with constant illumination, or with intermittently flashing illumination. For example, see U.S. Pat. No. 4,158,922 to Dana. The device described in the Dana patent does not provide means for extinguishing the illumination, whether constantly on, or if merely intermittently flashing. That is, the Dana device uses a mercury switch as a control device. Mercury switches are position sensitive whereby the illumination will stay on (or continue flashing) if the attitude of the is mercury switch places it in "on" position.
An alternative device is described, for example, in U.S. Pat. No. 4,848,009 to Rodgers. In Rodgers there is provided a footwear with a light source located thereon so as to be visible from the exterior of the footwear. In the Rodgers' device, a power source, a light source, and a circuit for selectively energizing the light source are provided. The Rodgers' device also includes a switch designed to alternate between "off" and "on" states in response to motion of the footwear, as well as a timing circuit. The timing circuit is responsive to the transition of the switch from the "off" to the "on" state and operates to turn off the light source after a predetermined time period and to prevent the light source from being turned on again until a further transition of the switch has occurred.
In the previously known illuminated footwear, the light source is an incandescent light bulb or a light emitting device (LED). Obviously, the use of LED's produces a bright display in selected colors and requires much less energy than an incandescent ilumination, thus giving longer battery life.